1. Field of the Invention
The present invention relates to a pressed powder cosmetic composition which has smooth and soft touch feeling, is excellent in feeling upon use and does not crack easily by an external force.
2. Description of the Related Art
A pressed powder cosmetic composition such as foundation, face powder or eye shadow is usually prepared by press molding, that is, solidification of a raw material composition, which has been filled in a container, by compression. Since a conventionally-employed pressed powder cosmetic composition contains an oil in a relatively small amount, a high molding pressure is required in order to overcome its weak powder-to-powder binding power. The press-molded product thus obtained is usually very hard and lacks soft touch feeling.
Lowering in the hardness of a pressed powder cosmetic composition, on the other hand, decreases its powder-to-powder binding power, which tends to cause cracking of the molded product of the composition by an external force.
A pressed powder cosmetic composition can also be prepared by the solvent method (Japanese Patent Application Laid-Open No. 108073/1981) wherein a mixed slurry, which has been obtained by mixing base materials including powder with a low-boiling-point organic solvent, is filled in a container, followed by removal of the solvent to solidify the slurry.
Although the solvent method is advantageous because it permits uniform filling of the mixture in a container, it is accompanied with the drawbacks that evaporation of a large amount of the solvent from the slurry during drying causes shrinkage or cracks, and the press-molded product in the container tends to be cracked by an external force or tends to develop caking.
An object of the present invention is therefore to provide a pressed powder cosmetic composition which has smooth and moisturized touch feeling, is excellent in feeling upon use, for example, easy release of powder, and does not crack easily.
The present inventors have found that a pressed powder cosmetic composition capable of attaining the above-described object is available by the use of a specific powder and a polymer having a specific modulus of elasticity in combination with an oil.
In the present invention, there is thus provided a pressed powder cosmetic composition, which comprises the following components (A), (B) and (C):
(A) a water-repellent and oil-repellent powder selected from the group consisting of fluorine resin powders and a powder having a surface treated with a fluorine compound,
(B) a film-forming polymer having a modulus of elasticity not greater than 200 kg/cm2, and
(C) an oil.
The present invention makes it possible to provide a pressed powder cosmetic composition which has smooth and soft touch feeling, permits easy powder release therefrom and is therefore excellent in feeling upon use, is free from cracks and is not broken easily by an external force. The pressed powder cosmetic composition of the present invention is suited, for example, as makeup cosmetic compositions such as foundation, face powder, cheek rouge and eye shadow.
The water-repellent and oil-repellent powder to be used as Component (A) in the present invention is selected from fluorine resin powders each originally having a water-repellent and oil-repellent surface and powders each having a surface treated with a fluorine compound. Examples of the powder to be treated with a fluorine compound include inorganic powders such as silicic acid, silicic anhydride, magnesium silicate, talc, sericite, mica, kaolin, red iron oxide, clay, bentonite, titanium-coated mica, bismuth oxychloride, zirconium oxide, magnesium oxide, zinc oxide, aluminum oxide, calcium sulfate, barium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, iron oxide, ultramarine blue pigment, chromium oxide, chromium hydroxide, calamine, and carbon black, and complexes thereof; organic powders such as polyamide, polyester, polypropylene, polystyrene, polyurethane, vinyl resin, urea resin, phenol resin, silicon resin, acrylic resin, melamine resin, epoxy resin, polycarbonate resin, divinylbenzene styrene copolymer, silk powder, cellulose powder, metal salts of a long-chain alkyl phosphoric acid, and N-mono (long chain) alkylacyl basic amino acid and complexes thereof; and complex powder of the above-exemplified inorganic powder and organic powder.
As the fluorine compound for treating the surface of the above-exemplified powder, a polyfluoroalkylphosphoric acid (U.S. Pat. No. 3,632,744) represented by the following formula (a):
[CxF2x+1CyH2yO]zPO(OH)3xe2x88x92zxe2x80x83xe2x80x83(a) 
wherein, x stands for 1 to 20, y stands for 1 to 5 and z stands for 1 or 2 can be mentioned as an example. Additional examples include fluoroalkyldi(oxyethyl)amine phosphate esters (Japanese Patent Application Laid-Open No. 250074/1987), fluoroalkyl-containing polymers (Japanese Patent Applications Laid-Open Nos. 167209/1980, 55481/1986, and 48803/1986), fluorine resins such as ethylene tetrafluoride (Japanese Patent Application Laid-Open No. 38707/1982), fluoroalcohols (Japanese Patent Applications Laid-Open No. 2251/1988 and 2252/1988), perfluoroepoxy compounds, sulfoamide type fluorophosphoric acid, perfluorosulfate salts, perfluorocarboxylate salts, perfluoroalkylsilanes (Japanese Patent Applications Laid-Open Nos. 318070/1989, 218603/1990, 160907/1989, 127477/1990, silane coupling agents such as xe2x80x9cLP-1T, LP-4T and LP-8Txe2x80x9d, each trade name; product of Shin-Etsu Silicone Co., Ltd.), fluorine-containing halogenated hydrocarbons (flon) such as trichlorotrifluoroethane (Japanese Patent Application Laid-Open No. 318070/1989), fluoroalkyl-containing polyhydric alcohols, fluoroalkyl-containing polyoxyethylene compounds (Japanese Patent Applications Laid-Open Nos. 180810/1989 and 180811/1989), fluoroalkyl-containing sulfoamide carboxylic acids, and fluoroalkyl-containing acrylate ester copolymers (U.S. Pat. No. 3,632,744).
Out of these, perfluoroalkylphosphoric acids and salts thereof, polyfluoroalkylphosphoric acids, fluoroalkyldi(oxyethyl)amine phosphate esters, perfluorosulfate salts, perfluorocarboxylate salts and perfluoroalkylsilanes are particularly preferred.
There is no particular limitation imposed on the method of treating the surface of a powder. It may be carried out in a manner known per se in the art. Based on 100 parts of the powder, the fluorine compound is preferably added in an amount of 0.05 to 20 parts by weight, more preferably 2 to 10 parts by weight for the surface treatment.
The water-repellent and oil-repellent powder as described above is incorporated into the pressed powder cosmetic composition of the present invention together with other powder as needed. The water-repellent and oil-repellent powder is preferably used in an amount not less than 50 wt. % in the whole powder components from the viewpoint of feeling upon use. The total amount of the powder in the whole composition is preferably 55 to 99.9 wt. %, especially 65 to 99.9 wt. %, more especially 75 to 99.9 wt. %.
As the other powder, those mentioned above for the surface treatment with a fluorine compound can be used without the surface treatment.
The film-forming polymer to be used in the invention as Component (B) is preferred to have a modulus of elasticity not greater than 200 kg/cm2, especially 1 to 200 kg/cm2, more especially 1 to 100 kg/cm2. When a polymer having a modulus of elasticity exceeding 200 kg/cm2 is employed, the product available therefrom becomes poor in feeling upon use with deteriorated softness or smoothness.
In the present invention, the modulus of elasticity was measured in the following manner.
A sample film for measurement was prepared by weighing 10 g of a 10 wt. % solution or dispersion of a film-forming polymer on a TEFLON-made Petri dish of 5 cm in diameter, naturally drying it for 5 to 10 days to form a film (0.3 to 0.5 mm in thickness), and cutting the film into strips, each 15 mm long and 5 mm wide. After the sample was allowed to stand at 25xc2x0 C. and relative humidity of 30% for at least 24 hours, it was fixed to a tensile test jig of a dynamic viscoelasticity measuring apparatus (xe2x80x9cRHEOSPECTRA DVE-V4xe2x80x9d, product of UBM) and its modulus of elasticity was measured under the conditions of an oscillation frequency of 10 Hz and amplitude of 10 xcexcm.
As the film-forming polymer having such a modulus of elasticity, that having a molecular weight of about 10,000 to 1,000,000 is preferred. Examples include polymers available by polymerization of at least one monomer having a polymerizable double bond, poly(N-acylalkyleneimine)-modified silicone (Japanese Patent Applications Nos. 112423/1993, 133352/1995 and 95705/1998), and vinyl-silicone block polymers (Japanese Patent Application Laid-Open No. 100307/1999). Examples of the monomer having a polymerizable double bond include hydrophilic monomers, for example, ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and fumaric acid, unsaturated carboxylate esters such as hydroxyethyl (meth)acrylate and polyethylene glycol mono(meth)acrylate, unsaturated carboxylic amides such as (meth)acrylamide and N-diacetone acrylamide, and amino-containing unsaturated carboxylate esters such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate and N,N,N-trimethylaminoethyl (meth)acrylate and salts thereof; and hydrophobic monomers, for example, aromatic vinyl compounds such as styrene, xcex1-methylstyrene, chlorostyrene and alkylstyrenes; acrylate esters and methacrylate esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, t-butyl (meth)acrylate and cyclohexyl (meth)acrylate; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, vinyl esters such as vinyl acetate, vinyl halides such as vinyl chloride and vinylidene chloride, fluorine monomers such as trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,3,3,4,4-hexafluorobutyl methacrylate, perfluorooctyl methacrylate and perfluorooctyl acrylate, and silicone macromonomers as represented by any one of the following formulas (1) to (5): 
wherein, R1 represents a hydrogen atom or a methyl group, R2 to R10 each independently represents a C1-6 alkyl group, C1-6 alkoxy group or phenyl group and n stands for 1 to 500.
As the poly(N-acylalkyleneimine)-modified silicone, preferred are those each having a poly(N-acylalkyleneimine) segment made of recurring units each represented by the following formula (6): 
wherein, R11 represents a hydrogen atom or a C1-22 alkyl, cycloalkyl, aralkyl or aryl group and m stands for 2 or 3, and an organopolysiloxane segment. Said poly(N-acylalkyleneimine) segment is produced by ring-opening polymerization of 2-oxazoline monomers or 2-oxazine monomers. Said poly(N-acylalkyleneimine) segment is bonded to the organopolysiloxane segment at the end thereof or as the side chain thereof through a hetero-atom-containing alkylene group. It contains the poly(N-acylalkyleneimine) segment and the organopolysiloxane segment at a weight ratio ranging from 1:50 to 20:1; and having a molecular weight of 10,000 to 500,000, particularly 50,000 to 300,000.
As the vinyl-silicone block polymer, that having, as structural units, a silicone polymer unit represented by the following formula (7): 
wherein R12, R13, R14 and R15 are the same or different and each independently represents a hydrogen atom, a C1-6 alkyl group or a nitrile group, R16, R17, R18 and R19 are the same or different and each independently represents a hydrogen atom or an alkyl or aryl group which may be substituted with a halogen atom, Y represents a linear or branched, saturated or unsaturated C1-10 hydrocarbon group which may be substituted by a halogen atom, A represents a xe2x80x94CONHxe2x80x94 or xe2x80x94COOxe2x80x94 group, B represents an xe2x80x94NHCOxe2x80x94 or xe2x80x94OCOxe2x80x94 group with the proviso that when A represents a xe2x80x94CONHxe2x80x94 group, B represents a xe2x80x94NHCOxe2x80x94 group, while when A represents a xe2x80x94COOxe2x80x94 group, B represents an xe2x80x94OCOxe2x80x94 group, q stands for 0 to 200, p stands for 0 to 6 and a stands for 2 to 300, and a vinyl monomer unit free of a fluorine atom; the total number of the silicone monomers constituting the silicone polymer unit of the formula (7) being 5 to 106, the total number of the vinyl monomers being 10 to 106, the sum of the total numbers of the silicone monomers and the vinyl monomers being 102 to 106, and a ratio of the total number of the silicone monomers to the total number of the vinyl monomers falling within a range of from 1:99 to 99:1 can be given as one example.
As Component (B), the film-forming polymer is preferably used in an amount of 0.1 to 15 wt. %, especially 0.5 to 10 wt. %, more especially 1 to 8 wt. % based on the whole composition.
As the oil of Component (C), oils including a fluorine oil are preferred. Examples of the fluorine oil include perfluoropolyether, perfluorodecalin, perfluorooctane and fluorine-modified silicone oils as described in Japanese Patent Application Laid-Open No. 180828/1999. As the perfluoropolyether, commercially available products such as FOMBLIN (trade name; product of Ausimont) and DEMNUM (trade name; product of Daikin Industries, Ltd.) can be mentioned by way of example. The oil (C) is preferred to contain the fluorine oil in an amount of at least 50 wt. % in order to attain good feeling upon use. Other oil components are those having no fluorine atoms. The oil (C) is preferably incorporated in an amount of 0.1 to 30 wt. %, especially 0.5 to 25 wt. %, more especially 0.5 to 20 wt. % based on the whole composition.
Examples of the above-mentioned oil components other than the fluorine oils include solid or semisolid oils such as vaseline, lanolin, ceresin, microcrystalline wax, carnauba wax, candelilla wax, higher fatty acids and higher alcohols; and liquid oils such as squalane, liquid paraffin, ester oils, diglyceride, triglyceride and silicon oils.
The pressed powder cosmetic composition according to the present invention preferably has a hardness, as measured by ASKER rubber hardness tester, C1L model, of 75 or less, especially 10 to 75; a porosity of 0.35 to 0.5, especially 0.37 to 0.5; and an impact resistance of 5 or greater, especially 7 or greater, because the composition having such properties is excellent in feeling upon use and crack resistance. The pressed powder cosmetic composition in the form of a foundation preferably has a hardness of 10 to 70, especially 10 to 67, while that in the form of an eye shadow preferably has a hardness of 30 to 75, especially 50 to 75.
The hardness is determined by directly measuring the hardness of the press molded product by ASKER rubber hardness tester (durometer), C1L Model (product of Kobunshi Keiki Co., Ltd.). In Preparation Examples which will be described later, the measurement was conducted by using a sample which had been filled in an aluminum pan of 54 mm in diameter and 4 mm in depth, press molded and then dried. The porosity was determined from the weight and volume of the molded product and true specific gravity of a powder bulk, based on the following equation:   Porosity  =      1    -                            Weight          ⁢                      xe2x80x83                    ⁢          of          ⁢                      xe2x80x83                    ⁢          molded          ⁢                      xe2x80x83                    ⁢          product                                                                    True                ⁢                                  xe2x80x83                                ⁢                specific                                                                                        gravity                ⁢                                  xe2x80x83                                ⁢                of                ⁢                                  xe2x80x83                                ⁢                powder                ⁢                                  xe2x80x83                                ⁢                bulk                                                        xc3x97              1                                                            Volume                ⁢                                  xe2x80x83                                ⁢                of                                                                        molded                                                          product                                          
In the above equation, the term xe2x80x9cmolded productxe2x80x9d means a cosmetic composition after molding and drying, while the term xe2x80x9cpowder bulkxe2x80x9d means a dried powder mixture which has not been molded and its true specific gravity is measured using xe2x80x9cAccuPyc, Model 1330xe2x80x9d, trade name; product of SHIMADZU Corporation).
The impact resistance was evaluated by the dropping frequency at which abnormalities such as cracks occurred when the above-described molded product was dropped in repetition from the height of 50 cm onto a plywood board of 25 mm thick.
To the pressed powder cosmetic composition of the present invention, it is possible to add, in addition to the above-described components, a surfactant, antiseptic, antioxidant, colorant, thickener, pH regulator, perfume, ultraviolet absorber, humectant, blood flow promoter, coolant, antiperspirant, bactericide, and/or skin activator as needed within an extent not impairing the advantages of the present invention.
The pressed powder cosmetic composition of the present invention can be prepared, for example, by mixing, the powder, oil, film-forming polymer having a modulus of elasticity not greater than 200 kg/cm2 and volatile solvent and then evaporating the volatile solvent to solidify the mixture.
Examples of the volatile solvent include water, low-boiling-point alcohols such as ethanol and isopropyl alcohol, hexane, isoparaffin, acetone, ethyl acetate and volatile silicone oil. Out of them, water and an aqueous alcohol solution are preferred.
Upon mixing, it is preferred to add the powder in an amount of 40 to 94.9 wt. %, especially 50 to 94.9 wt. %, the film-forming polymer in an amount of 0.1 to 14 wt. %, especially 0.5 to 10 wt. % and the volatile solvent in an amount of 5 to 40 wt. %. When the volatile solvent is added in an amount of 5 to 40 wt. %, the mixture thus obtained is in the form of a slightly wet powder. Amounts of the volatile solvent exceeding 40 wt. % are not preferred, because the mixture thus obtained becomes slurry as described in Japanese Patent Application Laid-Open No. 108703/1981, and during drying, shrinkage of the solid content occurs as a large amount of the solvent evaporates from the slurry, which causes a reduction in the porosity and makes the pressed product so hard as even to cause problems such as small cracks.
The pressed powder cosmetic composition is available by filling the mixture of the powder, oil, film-forming polymer and volatile solvent in a container and molding under pressure and then evaporating the solvent under proper conditions (temperature, pressure, time). The conditions of compression molding and solvent evaporation can be determined as needed depending on the kind, size or shape of a target pressed powder cosmetic product.